The present invention relates to a work output device, especially to a work output device that includes two motor rotors rotating a half circle up-and-down repetitively. The two motor rotors rotate from a lower position to a higher position when current is applied. When the power is off, the motor rotors turn back to the lower position. Thus a repetitive up-and-down half-circle rotation is performed by the work output device with stable rotating torque.
Natural sources on the earth including petroleum, coal, etc have been consumed dramatically after industrial resolution. With exhaustion of resources, nuclear energy has been used. However, nuclear energy and waste cause biological hazards and environmental impact. There is much fear of devastation due to main nuclear disasters and radioactive incidents occurred in recent years. Thus renewable energy such as wind, hydropower, tides, sunlight, etc is considered as an alternative fuel in future. Yet the development of the renewable energy and related techniques haven't matured enough to replace the petroleum completely. Thus energy saving is getting more important due to difficulties in development of new energy. In order to meet requirements of energy saving, there is a need to provide a work output device having stable rotating torque and providing better energy-saving effect and meeting requirements of more applications.